Dishwashers, such as those used in a home, may provide for a washing cycle followed by a drying cycle, the latter intended to dry the washed dishes sufficiently so that they may be immediately removed from the dishwasher and stored without additional manual drying. In many cases, the drying cycle includes activation of a heating element exposed at the bottom of the washing volume to heat the dishes and create an upward convective flow of hot air.
One drawback to vents is that they can increase the noise emitted from the dishwasher during the washing cycle and, accordingly, it is known to provide for vents having an electrically actuable door that may block the vents during the washing cycle thereby cutting emitted noise. One vent of this type is described in U.S. Pat. No. 6,293,289 entitled: “Surge Pressure Vent for Low Noise Dishwasher”. Venting can also be obtained by partially opening the door at the conclusion of the washing cycle as disclosed in U.S. Patent Application US 2004/0163684 entitled: “Automatic Door for Dishwasher”. Both of these patents are assigned to the assignee of the present invention and hereby incorporated by reference.
Venting systems can be improved by the addition of a blower to increase the passage of air through the washing volume. Generally, such blowers are arranged to reinforce the natural convective flow of air thereby obtaining the benefit from the blower and the convection action of the heated air during the drying cycle.
US patent application 2006/0231122, also assigned to the assignee of the present invention, describes a blower that obtains improved drying efficiency by operating at very low flow volumes in a direction counter to the natural convective flow of the air. This application also describes a vent door actuated by a solenoid or the like.